73 transforming to 79 disc brakes

[CRAZY EDDS RATSUN WORKS]

ive got the ultimate ratsun as datdoug would say i was wondering my truck is a 73 and i took the disc brake whole assembley off the 79 front was wondering if anybody has done the swap and could give me some info or relay it to datdoug therefore i am poor and do not have internet access all month long hahha if you seen my clothes you would say im poor hahahah

[mklotz70]

I'm pretty sure my answer is the same as it was on nwde :) Check with beebani though...his might have changed.

[lynchfourtwenty]

negatory on that mike.. im going to take him my truck soon an let him fab directly to it.. so there will no longer be any problems an then people can get sets that work perfectly without issue

[BEEBANI]

Yeah, uhhh, yours will work perfectly without issue. Watch the wording there Josh, yours is the only one I've had problems with so far. I have a guy in socal I just talked to on the phone last week who has his on with the old design and has had no complaints at all. I walked him through getting the master cylinder upgraded to the 280zx one and he is very happy with the results.

 

Like I told you before, the bigger wheels with the spacers is why you noticed the steering issue. Most guys are still running 14" stockers and don't have that issue. My original design has been working fine for many guys, but I decided to do a redesign to fix your issue and keep it from being an issue for any other guys that decide to run bigger/wider wheels.

[BEEBANI]

ive got the ultimate ratsun as datdoug would say i was wondering my truck is a 73 and i took the disc brake whole assembley off the 79 front was wondering if anybody has done the swap and could give me some info or relay it to datdoug

 

I think Mike stated before that the '78 and up front suspension will not mount to a pre-78 truck because of the geometry of the mounts. I had to make new upper and lower control arms to adapt ball joint front suspension to my truck.

 

I don't plan on doing anything to make it possible to mount the 620/720 discs and calipers to the older kingpin trucks. The rotors are small and the calipers weren't that good when they were new, so better to either use the hardbody/passport setup or the 300zx/passport setup.

 

Hope this helps.

[CRAZY EDDS RATSUN WORKS]

I Have The The Whole Complete Disc Assembly With Control Arms And All Was Tough To Take Off 79 And I Have The Brake Booster And Master To Why Wont That Whole Assembly Bolt Up A Arms And All Just Curios

[]2eDeYe]

It might bolt up (I have read that it does, haven't tried it).

You will have shorten (or lengthen, not too sure) your lower control arm to correct the camber issue that will surely rear it's ugly head :P

 

Keep your eye out for a set of spindles, rotors and calipers for a hardbody. These will swap right onto the 79 balljoints and will upgrade you to a vented rotor and better caliper design.

I have 1995 frontier brakes on my 1979 620 ;)

 

I opted to get 2" drop spindles for a hardbody giving me a bit more shock travel and better control arm geometry. I like my datto low :D

[datzenmike]

The wretched disc brake design used on the '78 trucks was continued through till '83 when it was up-graded to vented rotors and beefier calipers. They were still better than front drum even if they were kept adjusted.

[lynchfourtwenty]

well if theres an issue with my truck theres going to be issues with other trucks.. weather or not they notice it... i had no problem flippin u turns before.. even with the tire size.. i maybe agree that tire size amplifies the problem but either way you look at it Theres a problem... im just tryin to help u and everyone out by donating my truck to science so that people can have disc brakes And flip U turns lol

[1lo620]

Hell, I say do what my friend did to his 73...He took the front end of a 79 cut it right behind the fire wall and welded it onto his 73...look disc brakes....But I will say this was about 15 yrs ago...cool thing is that he still has it. If I could ever figure out how to print pics I would show you his truck.

[lynchfourtwenty]

you mean scan?? do you have the pictures on your computer or are they like "photographs" that you would have to scan.. ?.. the setup we're talking about uses a wider selection of nissan calipers that are cheap to get .. the brakes work great!!!!!!!!!!!! but i cant do u-turns or pulling into parking spaces some times takes 2 - 3 manouvers

[datzenmike]

I Have The The Whole Complete Disc Assembly With Control Arms And All Was Tough To Take Off 79 And I Have The Brake Booster And Master To Why Wont That Whole Assembly Bolt Up A Arms And All Just Curios

 

I think the torsion bar mounting points are in a slightly different place than the king pin trucks, so the lower control arm, maybe the upper too, would be in ,or out, too far. Believe me if it was a bolt in job everyone would have done this to get disc brakes.

[kiznook]

Wheel/Tire size IN NO WAY effects the relationship between the cliper bracket and tie rod end(i think thats what it was hitting).

[BEEBANI]

No, the lower mount on the bracket where it attaches to the rotor was hitting the hex shaped grease cap on the lower control arm. All I was saying is that he has wheel spacers which makes his track width wider, therefore he has a different turning radius than someone with stock spaced wheels.

 

I just don't want to start making generalizations about my design until I can rule out that it's not just a one-time thing.

 

I appreciate Josh offering up his truck for "science" because all I have to test with is the front suspension out of a 620 that isn't bolted to truck. There's a lot of variables there that I can't recreate without a truck.

[lynchfourtwenty]

well hopefully soon i can drive her down an let ya tinker with her :)

[mklotz70]

Geez...where to start. I'll try to keep this somewhat short, but I can't figure out how to NOT come off sounding like an a**hole. If I do..oh well...I'm sure the guys on here that know me will know where I'm coming from ...anyway...

 

First off...on the topic of will the '79 stuff fit. Like I said before...yes it will fit. Will if be right? NO! Will it drive safely? NO! Am I going to spend anymore time answering that question again...probably not. The nicest way I can put it is go read the thread you were given a link to....or go ahead and bolt the stuff up and take pics...then do a how-to thread on here about it. What's taught is twice learned. You can use a good bit of what you have, but it will require custom parts to make it work right...now go find the rest of the answer :)

 

As for Beebani's prob with Lynch's brakes. I haven't looked at just how bad they are hitting. He said they're hitting the lower fulcrum pin nut. If all of your brackets are identical, then I'd seriously question just how many other guys have actually bolted them up. His wheel/tire combo will not affect his turning radius unless they are rubbing on the inner fender well or frame. The geometry dictates that the tires still point at the same angle in a turn. Plus...he had them on before the disc brakes so the only thing that changed is the bracket hitting the fulcrum pin nut. I'd bet that once the other guys start mounting theirs up, you'll be hearing about it.

 

The front suspension doesn't need to be bolted up to the truck, it simply needs the lower control arms connected to the dogbone.

 

I'm sure a couple of guys out there know just how hard I'm biting my tongue right now. :)

[datzenmike]

There's blood on your teeth mike.

[kiznook]

lol. gotta remember that lynch's truck is VERY much a daily driver

[lynchfourtwenty]

lol. gotta remember that lynch's truck is VERY much a daily driver

 

he's right on that.. my trucks driven every day.. to where ever i need to go..

[]2eDeYe]

you mean scan?? do you have the pictures on your computer or are they like "photographs" that you would have to scan..

 

Dave has so many awesome pics from shows back in the day it's unreal. He needs to pick up a scanner real bad :eek:

 

He also needs to get a digital camera ;)

[BEEBANI]

Well, not sure what you're biting your tongue about, but like I've said, I have several guys that have them bolted on (talked to them personally on the phone) and I talked to them after lynch told me of the steering problem, and none of them had an issue with it.

 

But, nonetheless, I've completely redesigned the bracket to put the caliper up higher and to cure the hitting issue with the lower arm. I have the lower arm mounted to my mock up unit but that doesn't tell me how far the wheels need to turn because again; it's not mounted to the truck with a wheel on it.

 

Anyway, as I've stated before; I'm not trying to get rich off of anyone here, just want to provide a service and maybe earn a little "project cash" along the way. I have stopped selling them until I get lynch's truck down here and we can test everything out.

[lynchfourtwenty]

my trucks a project whore... anyone else notice that? theres always Somethin i gotta do.. like now i get this weed whacker sound when i let off the gas it has something to do with the clutch i think.. but its that buzzing sound like a weed whacker makes.. not as loud but same type of noise... god i hate funny noises!

[kiznook]

I don't think tha tking the truck down there is going to help at all. It's pretty simple. 1st, The caliper must be raised so the bracket doesn't his that pin. 2nd, when metal gets hot it tends to bend and twist, generally reffered to as "warping". This is most common when applying lots of weld in a small area, creating more heat.

The new design seems to position the caliper in the right place, now you just need some quality control to make sure the ears are in the right place. THE SAD PART is that this time you could have caught it by simply trying to install in a spindle. HELL you could have caught it by laying a straight edge across the caliper mounting points.

 

That first bracket will have the same problem on any truck. STOP saying that it was just lynch's

[DISLEXICDIME]

wow this is so hi school :) i know some one here who can make josh a set of brackets that will work (you know who you are:rolleyes: . hook him up. then evorey one will be happy. just dont let him tell any one who maid them for him. because i know you don't want evorey one bugging you for them.

[lynchfourtwenty]

hey now dont drag me into the highschool stuff! lol nah for real i aint tryin to bitch anyone out.. he's tryin to make it right an thats cool.. but for real tho.. any helps appriciated..